Heretofore, a typical tennis racquet structure has included a bow and yoke collectively referred to as a head, a throat or shaft, and a handle. More specifically, the head has included an elliptical or circular bow containing attached, interlaced strings under tension. The bow conventionally has been attached to a handle through a variety of designs of throats or shafts, ranging from solid shafts to concave splayed, split shafts which typically are tangentially connected to the proximal-outer portions of the bow. The yoke usually has been located near the open proximal portion of the bow to form the lower portion of the head, extending between the inner surfaces of the bow at the transition from the convex bow to the concave shaft of the racquet frame. The yoke inhibits torsional movement of the bow by anchoring the proximal ends of the bow to each other. In addition to preventing torsional movement of the bow when a ball is struck, the yoke also has served to limit the proximal-to-distal string length which in turn inhibits trampolining which might otherwise occur if the yoke were not present and the strings were longer. Moreover, the yoke stabilizes the bow during stringing of the racquet.
However, despite such advantages, the presence of the yoke interrupts the flexion pattern of the bow. Causing the torsional movement of the bow to forcibly come to such an abrupt end creates a sharply defined stress riser zone in the racquet at the junction of the bow and shaft. Thus, such shear forces which break up the bending modes as a result of yoke placement, at the least, cause unfavorable vibrations which are transmitted to the player's hand, and at worst can cause racquet failure.
Attempts have also been made to improve prior art tennis racquets through continuing advances in metal and composite technologies. These advances have made such materials the choice for most modern tennis racquet frames due to their ability to further improve the stiffness of the frame while reducing the weight thereof, resulting in improved power. However, this increased stiffness has resulted in a significant decrease in the duration of the shock impulse transmitted to the player's hand upon impact of a ball with the racquet strings, which effectively increases the strength of the jolt transmitted to the player's hand, which in turn adversely affects the playability of the racquet. Moreover, the increased height of the bow of many prior art racquets together with the use of such advanced composite materials, also adds to the stiffness of the bow, resulting in further increase in the shock felt by the player upon striking the ball. Thus, the trend in tennis racquet design toward increased stiffness and reduced weight has caused most racquet designers to search for a combination of design elements which maintain power, reduce shock and improve feel, through disposition of the sweet spot of the racquet to a more distal location, or in other words, closer to the general area of ball impact with the strings in most cases. The sweet spot generally is universally defined as being comprised of three separate elements, including, the area of highest coefficient of restitution of the racquet or the area of greatest power, the center of percussion of the racquet or the point at which the racquet will not twist or torque longitudinally or latitudinally, and nodal point or area of the strung face of the racquet where minimal vibration occurs upon ball impact.
However, the advent of racquets having generally larger heads has effectively proximally relocated the sweet spot, or in other words, reduced the distance of the sweet spot to the player's hand. This reduction in distance results in reduced leverage for the player, which especially effects longer and faster strokes, such as the service. One hallmark of the larger headed racquets is that the proximal end of the head lies closer to the handle area. It follows that the central portion of the head also is located closer to the handle. As a result, the three elements comprising the sweet spot all are located at or below the latitudinal center of the head, resulting in a loss of leverage for the player. To illustrate this point, a typical wood racquet circa 1960 has a longitudinal head length of 10.69 inches, while a large head racquet circa 1970 has a longitudinal head length of 13.25 inches. All other dimensions being equal, the center of the large head racquet is more than 1.25 inches closer to the player's hand than the small head wood racquet. Thus, the problem exists of disposing the sweet spot at a more distal location on the head while enjoying the advantages of a large headed racquet, such as greater tolerance on mishit shots.
Light-weight, large-head racquets generally have a reduced swing weight which does not allow a player to achieve the same amount of momentum in the head area as is possible with heavier, more traditional racquets having a smaller string area. In other words, players have had to sacrifice power to attain the benefit of a lighter racquet with a larger hitting area.
Attempts to provide a light-weight, large-head racquet with a better swing weight have been generally directed toward reducing the weight of the handle position using strong, light-weight materials. This has resulted in a racquet which tends to transmit an uncomfortable, sometimes painful, jolt to the player's hand if the ball is struck in an area which is not very close to the center of percussion, thereby providing an inferior feel which can be potentially injurious to players who frequently strike the ball away from the center of percussion.
Accordingly, a light-weight, large-head racquet having a relatively high swing weight yet having a handle weight sufficient to provide a more comfortable feel when the ball is struck away from the center of percussion is highly desirable.